Refuelling, Charging & LPG

Where should a gas (LPG) cylinder forklift ideally be refuelled or have its cylinder changed?

• AIn a small enclosed store cupboard next to the boiler room so the cylinders stay warm
• BIn a well-ventilated area away from sources of ignition, drains and pits✓
• COver an open drain or inspection pit so that any escaping gas can run away below
• DNext to the site cigarette break area where staff can keep an eye on the cylinders

Answer: LPG is heavier than air and flammable, so cylinder changes should be done in a well-ventilated place away from ignition sources, drains and pits where escaping gas could collect. This reduces the risk of a flammable build-up.

While charging a lead-acid battery on an electric forklift, what hazardous gas is given off that must be ventilated?

• APure oxygen only
• BHelium, which is completely inert and therefore needs no special ventilation
• CHydrogen, which is highly flammable and explosive✓
• DNitrogen, which is not flammable and can be left to disperse without ventilation

Answer: Charging a lead-acid battery produces hydrogen gas, which is highly flammable and can explode if it builds up near a spark or flame. Charging areas must be well ventilated and free of ignition sources, with no smoking allowed.

Which personal protective equipment is particularly important when handling or topping up a lead-acid forklift battery?

• AA high-visibility vest and a hard hat, with no eye protection or gloves required
• BNo PPE is needed at all, because the battery sits in an enclosed steel tray throughout
• CEye protection and acid-resistant gloves, because the electrolyte is corrosive✓
• DEar defenders only, because the charger's cooling fans are the main hazard present

Answer: Battery electrolyte is dilute sulphuric acid, which is corrosive to skin and eyes, so eye protection and acid-resistant gloves should be worn. An eyewash station should also be available in case of splashes.

Smoking or using a naked flame near a forklift refuelling or battery charging area is:

• AEncouraged to help warm cold batteries
• BStrictly prohibited because of flammable fuel vapours and hydrogen gas✓
• CAllowed only during night shifts
• DAllowed provided you stand at least one step away from the charging bay doorway

Answer: Diesel and LPG vapours and the hydrogen released during battery charging are all flammable, so naked flames and smoking must be strictly prohibited in these areas. A single spark could cause a fire or explosion.

How should spare LPG cylinders be stored?

• AUpright and secured in a ventilated outdoor store, away from drains and ignition sources✓
• BLying flat in a locked indoor cupboard so they cannot be knocked over
• CUpright inside the warehouse beside the battery charging bay, where they are easiest to reach
• DIn any secure location, since a closed cylinder valve makes the storage position irrelevant

Answer: Upright keeps the valve in the vapour space so a leak releases gas rather than liquid. Ventilated and outdoors means a leak disperses instead of accumulating, and away from drains and pits matters because LPG is heavier than air and sinks into them. Secured means they cannot fall and damage the valve — the part most likely to fail.

Why is it important that LPG is heavier than air?

• AAny leak sinks and collects in pits, drains and low spots rather than dispersing✓
• BIt means a leak rises quickly to roof level where it disperses harmlessly
• CIt makes the cylinders heavier, so they must be lifted with mechanical aids
• DIt allows leaks to be detected easily because the gas is visible near the floor

Answer: This single property drives most of the LPG rules. Because it sinks, escaping gas pools invisibly in inspection pits, drains, basements and floor voids, where it can sit until something ignites it. That is why cylinder changes happen away from drains and pits, why storage is ventilated at low level, and why a leak near a pit is treated as serious. It is not visible.

What should be done before disconnecting an LPG cylinder from a truck?

• ADisconnect the hose first so that any residual pressure escapes to atmosphere
• BClose the cylinder valve fully and follow the manufacturer's shutdown procedure✓
• CStart the engine and run it at full throttle to empty the fuel lines quickly
• DLoosen the coupling slightly and wait for the hiss of escaping gas to stop

Answer: Close the valve first, then follow the procedure for the truck — which on many machines means letting the engine consume the gas left in the line before disconnecting. Disconnecting under pressure, or cracking a coupling to vent gas deliberately, releases LPG exactly where you are standing. Gloves and eye protection matter too: liquid LPG causes cold burns.

What must happen before a diesel or petrol lift truck is refuelled?

• AThe engine must be switched off, with no smoking or naked flames nearby✓
• BThe engine must be left idling throughout so that the fuel system stays primed
• CThe forks must be raised fully so that the fuel filler cap is easier to reach
• DThe truck must have a thorough examination certificate on board

Answer: Engine off removes the main ignition source right next to where vapour is being released, and it stops the truck moving off with a nozzle in the tank. No smoking and no naked flames extend to the whole refuelling area. Spills should be cleaned up rather than left — diesel on a smooth floor is a slip hazard long after it stops looking wet.

Why must metal tools not be laid on top of a lead-acid traction battery?

• AThe extra weight on the battery casing can crack the cell containers
• BThe tool will be corroded by acid vapour and become unusable
• CA tool bridging the terminals causes a short circuit, with sparks and burns✓
• DMetal objects interfere with the charger's ability to sense the charge state

Answer: A traction battery can deliver an enormous current. A spanner across the terminals shorts it, and the result is a violent arc, a red-hot tool welded in place and burns — with hydrogen from charging often present as well. Keep tools off the battery top, use insulated tools where work is needed, and remove watches and rings before working near terminals.

What should be done before connecting or disconnecting a battery from its charger?

• ASwitch the charger off first, so the connection is not made or broken under load✓
• BConnect while the charger is running so the charge begins immediately
• CTop up the electrolyte first, so that the cells are completely full before charging starts
• DRun the truck until the battery is completely flat, which protects its overall lifespan

Answer: Making or breaking a connection under load draws an arc at the connector, and a charging area is exactly where hydrogen may be present. Switch off, then connect or disconnect. Topping up is done after charging, not before, because the electrolyte level rises during the charge — and completely discharging a traction battery damages it rather than helping.